# Exhaust fan advice



## Warren (Apr 6, 2007)

Hey guys I need some advice from those of you who have exhaust fans in your smoking room.

Last spring I turned my garage into a home office. It's about 800 sq ft. I wanted to be able to smoke inside so I installed two exhaust fans (one at each end) plus a big ceiling fan right in the middle. The setup works fine over time. If I finish a cigar, turn on the fans, and wait about 30 minutes the air is cleared out and the smell is minimal. The problem is since it can't suck the smoke out of the room immediately when I exhale it is sticking to my pictures, walls, floors, furniture, computer, etc. I'm having to dust and clean every 3-4 days.

Right now I have two bath room style exhaust fans mounted in the ceiling. They do a fine job of cleaning over time but are not strong enough to pull the smoke out immediately. The ceiling fan helps pull it up and away from me but basically just slings it around. I've tried various combinations of ceiling fan on/off, exhaust fans on during/after smoking, windows open/closed, door open/closed, etc.

So I'm going to get a new exhaust fan or two. If you have any experience in this area let me know what you suggest. I really do not want to buy more equipment that I will just have to replace in a year.

Oh and the one catch... power is limited. I already had two 15 amp lines going to the garage. I didn't want to bust up concrete and add more power so I have a total of 30 amps to work with between fans, lights, TV, computer, etc. 

Thanks in advance.


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## RJpuffs (Jan 27, 2008)

Exhaust fans are rated in CFM - Cubic Feet per Minute. Obviously the higher the CFM the more air is going to be exchanged. Note that the higher the CFM (power), the louder the s.o.b. gets. I have a fan that is deafening, it barely clears the room after an hour and my ears ring for twice as long. The little potty-freshener fans just barely work to dissapate the aftermath of a big dump - they just can't handle a cigar.

You need a "clean" air return that brings in fresh air (cracked/open window will do it). The faceplate of the exhaust fan may need to be modified or removed to get the most airflow.

But smoke sticking to things is bound to happen, spray fabreeze all over the walls? :ask:


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## asmartbull (Aug 16, 2009)

A buddy of mine put a bathroom exhaust fan directly over his desk
and cut some slits in his door for fresh air.
He sometimes puts a small space heater near his desk to help the smoke filled air rise faster
Works like a charm........


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## ongreystreet (Nov 3, 2008)

First of all, can we verify that you have an 800 sq ft garage/office?

You're typical Lowes/HD exhuast fan is only going to move around 50 - 100 cfm.

I would suugest look on grainger.com, grainger is a great starting point since they sell everything. I would suggest kitchen not restroom, although in some cases they are pretty much the same thing. You can find exhaust fans there under 2 amps that move 200-500 cfm.

Another issue you want to look into is supply air, all that air your exhausting has to be replaced, where is there air currently coming from?


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## Warren (Apr 6, 2007)

The two fans I have now are 80 CFM. So my room is 800 sq ft x 9 ft ceilings = 7200 cf. By my math the two fans I have should replace all the air in my room in about 45 minutes. And it seems to do that.

But I wish I had something that would suck the smoke straight out of the room as soon as I exhale it. I know such a product exists because I've been in lounges before with 4-5 other smokers and it was whisked up and out with every puff. I think if I could find one like that it might be worthwhile to buy.


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## Warren (Apr 6, 2007)

ongreystreet said:


> First of all, can we verify that you have an 800 sq ft garage/office?
> 
> You're typical Lowes/HD exhuast fan is only going to move around 50 - 100 cfm.
> 
> ...


Yeah I'm thinking that is my problem, two small units does not equal one larger one. I should have known that.

My air supply is a combination of open windows and doors.

Thanks for the tip I'll look at Granger.


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## Warren (Apr 6, 2007)

Anyone have experience with inline exhaust fans? I'm thinking that might be the way to go. I could mount the loud motor in the attic and not deal with deafening noise.


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## smelvis (Sep 7, 2009)

Silly question but are they fighting each other? By one at each end are they working together other apart?


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## Warren (Apr 6, 2007)

smelvis said:


> Silly question but are they fighting each other? By one at each end are they working together other apart?


I think they are far enough apart to not fight each other. I have about 25 feet between them.


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## smelvis (Sep 7, 2009)

Warren said:


> I think they are far enough apart to not fight each other. I have about 25 feet between them.


Probably just have to go bigger then, Granger is expensive, I would look online!

Good Luck!


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## pakrat (Feb 10, 2008)

If it were me, first thing I would do is leave the ceiling fan off. That would let the smoke rise and be pulled out in a higher concentration (assuming the exhaust fans are mounted high). I would also put the exhaust fan/fans (highest cfm that you can find) at one end of the room where you normally smoke and put the opening for the incoming air down low at the other end of the room. Maybe even put a fan on the inlet air opening pushing air into the room.


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## sboyajian (Jun 27, 2008)

I have a 6" Centrifugal multifin exhaust fan (435CFM).. once the ducting is on it's not that loud. I had a lot of noise by the actual vent box where it pulled the air in, but this weekend we replaced the last stretch of ducting with some insulated flexi duct and the sound went away.

Believe it or not, my fan was only $120. It comes with a plug, to plug into an outlet.. I wired mine up to a $9 Lutron fully variable control (model FS-5F).

They also make a 4" version which is about $100 which does 171 cfm.(R & M Supply, Inc. - ValuLine Fans)

To be honest, the extra potential 250 cfm is worth the $20, and with a variable control, you can simply run it at half throttle.

Believe it or not, my fan has a 1.5A Draw.. it's running on a 15A circuit right now along with some outlets and lights.

I believe the biggest issue, regardless of fan size is this comment right here:



> The problem is since it can't suck the smoke out of the room immediately when I exhale it is sticking to my pictures, walls, floors, furniture, computer, etc. I'm having to dust and clean every 3-4 days.


Is there a reason you can suck it out immediately? The sitting in the room is the problem, not the size of your exhaust.

Also, make sure the ceiling fan is switched to pull air up. Most fans allow you to change direction based on Summer/Winter. If you are blowing the air back down, it's kind of counter productive.

I know some else asked this, but can we get a verification on that garage size? 800 sq ft is equivalent to a 20' x 40' basement.. that's a big damn garage. If that's the case (7200 cu. ft) you're going to need a minimum of 400 cfm and it's going to HAVE to be on the whole time.


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## Warren (Apr 6, 2007)

Yes it is 800 sq ft. I had a detached 3-car garage when I bought my house. I never used it so last spring I converted it into one big office/mancave. 

The ceiling fan is set to pull up. I thought that might help get the smoke off me and up to the exhaust fans faster. At least that was my theory. In reality I think it throws around too much air and spreads the smoke around the room and back down the walls. So yeah I'm experimenting with turning it off.

I re-checked and my two fans currently are actually 110 CFM. Which totals 220 CFM for both units. My office is 7200 CF so that's about 32 minutes to clean all the air. Not bad but not quick enough to prevent some of the smoke from settling.

I'll keep playing with it and looking. Thanks for the all advice. I'll update the thread with what works and what doesn't work in case someone else is in the boat.


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## Jenady (Nov 23, 2009)

Warren,

I know this is not the direction you are thing of but it works well for me. I smoke in my office at home. I set this up and run both sides on low. It keeps the room clear of smoke. I understand that cold air is coming in the house but I try not to think about that. :mrgreen:










$35 from Amazon.


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## havanajohn (Apr 4, 2009)

Where is the 'clean air' coming from? Do you have a intake vent?


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